Enrichment of Methane Concentration by Removing Contaminant Gases from Biogas Mixtures Based on Chemical Purification Processes
Muhammad Rashed Al Mamun and Shuichi Torii
This paper presents an experimental study on the application of chemical technology to biogas purifying before utilization. The presence of H2S, CO2 and H2O in the biogas has corrosion effects on metallic components and may also lead to detrimental effects on health and lowering the heating calorific value. Removal of these contaminants from biogas can therefore significantly improve the gas quality. A chemical purification process was investigated for removal of contaminants from biogas. Two types of chemical mixtures were used: phase 1 (Feo, CaO and silica gel) and phase 2 (Fe2O3, CaO and Na2SO4) mixtures. The results show that the removal efficiency of H2S, CO2 and H2O from biogas mixtures of 83.2%, 83.8%, 95.4% and 79.8%, 80.4%, 81.7%, in phase 1 and 2, respectively with a corresponding CH4-concentration enriched of 95.5% and 89.7%. We propose that this methane enrichment process might be useful for cleaning and upgrading of biogas quality.
Keywords: Biogas, chemical purification process, methane, hydrogen sulfide (H2S), carbon dioxide (CO2), water vapor (H2O)